Abstract: A fuse is provided which has a fuse housing with a transparent portion thereof, and a fuse element extending through the housing which is coated with a preferably non-hazardous temperature-responsive material. The temperature conditions generated at the interface between the coating and the fuse element cause the coating to leave the fuse element and deposit upon this transparent portion of the housing. The temperature-responsive coating on the fuse element will be transferred to the housing walls even where modest current overloads flow which do not immediately open the fuse. Different circuit overload conditions, including short circuit events, produce different visual indications or colorations on the transparent housings inside surfaces, which serves to identify the nature and degree of the overload problem existing in the circuit. Coatings, also capable of fluorescing under specific irradiation conditions, may be used.